The invention relates to a navigation system for a vehicle and more particularly to a navigation system including a method for determining fuel usage to reach a desired destination and a fuel filling station nearest the destination.
A navigation system for a vehicle has become increasingly popular as an accessory in the vehicle. The navigation system assists a driver by locating destinations, providing information regarding fuel efficiency, and providing other useful information.
Certain navigation systems, such as that disclosed in U.S. Pat. No. 5,742,922, calculate a route to a destination according to fuel consumption. The navigation system disclosed in the ""922 patent permits alternate routes to be selected based upon calculated fuel efficiency.
It would be desirable to produce a navigation system for a vehicle which calculates an expected fuel consumption to a destination, as well as from the destination to the nearest fuel filling station to assist a driver in planning for fuel stops as needed and avoid running out of fuel.
Consistent and consonant with the present invention, a navigation system for a vehicle which includes a method for calculating an expected fuel consumption to a destination, as well as from the destination to the nearest fuel filling station has surprisingly been discovered. The method for determining fuel usage for a vehicle in a vehicle navigation system comprises the steps of: entering a destination in the vehicle navigation system; calculating a first route to reach the destination; calculating approximate fuel usage required for the vehicle to reach the destination by the first route and to reach a fuel filling station closest to the destination; comparing the calculated fuel usage required for the vehicle to reach the destination by the first route with a quantity of fuel remaining in the vehicle; and displaying a message that the destination and the fuel filling station closest to the destination cannot be reached when the fuel remaining is less than the calculated fuel usage required for the vehicle to reach the destination by the first route and the fuel filling station closest to the destination.